1. Field of the Invention
This invention pertains to collapsible shelters, such as tents, canopies, and sun-shades. More particularly, the present invention pertains to a hub for connecting support poles of a shelter in a manner such that the poles that are directly attached to the hub are not all rigidly connected to each other.
2. General Background
Collapsible shelters, such as tents, canopies, and sun-shades often comprise a pliable shell supported by a plurality of structural poles that can be selectively detached from each other, or otherwise collapsed, in a manner such that the shelter can be selectively erected and, alternatively, collapsed. In some cases, the structural assembly of poles is configured to be separated from the pliable shell as the shelter is being collapsed. More recently, it is becoming common to configure a collapsible shelter such that its structural poles remain connected to each other and to the pliable shell of the shelter when the shelter is collapsed.
There are two very common types of pole assemblies used in connection with collapsible shelters. One type utilizes a plurality of poles that are held together via an elastic cord (often called shock cord) that passes longitudinally through the hollow centers of a plurality of poles in a manner such that socket fittings are sufficient to maintain the poles in an erected configuration. Another type utilizes poles that are hinged or telescoping. In general, the former is lighter than the latter and the latter is generally more rigid and strong. The present invention can be used in connection with either type of pole assemblies.
Although the assembly of poles provides support for the pliable shell, in many cases the pliable shell of the shelter works in concert with the assembly of poles to structurally support the shelter in its erected configuration. In other words, the pliable shell of a collapsible shelter often serves as tension and shear panels that prevent the pole assemblies from buckling or twisting. Thus, the pole assemblies need not be self-supported.
In an effort to reduce the weight of collapsible shelters to facilitate the transportation of such shelters, the structural poles are typically minimally sized for anticipated load requirements. As a result, the fittings and other components that connect the poles to each other in their erected configuration, and the poles themselves, can experience high bending stresses. This can lead to component failure or fatigue.